CHESAPEAKE, Virginia (CNN) --The case of sniper defendant Lee Boyd Malvo went to jurors Tuesday with the teenager's attorney arguing his client was under the spell of mastermind John Allen Muhammad, while the lead prosecutor implored the jury to see through the "smokescreen" of Malvo's insanity defense.

More than five weeks after the trial of Malvo began, Circuit Judge Jane Marum Roush sent the case to the jury just after 4 p.m. EST Tuesday. They picked a foreman and were sent home until deliberations begin Wednesday morning.

Malvo, now 18, is accused of killing of Linda Franklin at a Home Depot in Fairfax County, Virginia, on October 14, 2002. Her death was one of 10 fatal sniper attacks that terrified Washington, D.C., and outlying areas. Three people were wounded in other attacks.

If convicted, Malvo could face the death penalty.

Malvo has pleaded not guilty to the charges by reason of insanity. His lawyers argue that the alleged brainwashing their client suffered from Muhammad was so severe that the teenager – who was 17 during the time of the shootings -- was legally insane and unable to tell right from wrong.

Last month, a jury convicted Muhammad for his role in the sniper shootings. The jury in that case recommended the death penalty.

In closing arguments Tuesday, defense attorney Michael Arif said a police confession by Malvo was "not believable," and said his client took responsibility for the shootings to take the blame off Muhammad, the man Arif said Malvo came to see as his father.

"Lee Malvo is gone," Arif said. "What you have now ... you have John Muhammad Jr."

Prosecutors, however, say both Muhammad and Malvo share blame for last year's shooting spree.

Prosecutor Robert Horan Jr. told jurors not to buy insanity arguments by the defense -- that Malvo knew exactly what he was doing when he allegedly fired the shot that downed Franklin.

"Even if you want to assume he was brainwashed, hard life is not mental disease," Horan said. "It is a smokescreen. The real issue here is October 14, 2002, when he sighted that rifle across that highway and shot Linda Franklin in the head, did he know it was wrong? We submit that he did."

Defense underscores indoctrination claim

In his closing arguments, Arif took a shot against the imposition of a death penalty, saying "the pain inflicted" on victims and families in the sniper shootings "is inexcusable" but "adding another life to that pile of death is not going to solve anything."

He noted that one psychologist who examined Malvo in jail characterized Malvo as "goofy," saying he smiled inappropriately.

In his closing, Arif put together a case implicating Muhammad as the leader and mastermind of the crime spree.

Of Malvo's confession to police, Arif told jurors "it is not believable" and "frankly, it's bull. It's not real. It's nonsense. He's putting the blame on himself" to take the heat off Muhammad.

Arif said Muhammad slowly indoctrinated Malvo by isolating him from family and friends.

Muhammad also indoctrinated Malvo by using rigorous exercise, controlling his diet and personal hygiene, exposing him to violence, playing audiotapes under Malvo's pillow as he slept, and encouraging him to suppress his feelings.

"Right was what John Muhammad said it was. Wrong was what John Muhammad said," Arif said. "Did he (Malvo) know the acts were illegal. Probably. But that was not what was important. Right or wrong is what John Muhammad said it was.

"Lee could no more separate from John Muhammad than you could separate from your shadow on a sunny day," Arif told jurors.

Prosecutor: Malvo, Muhammad equally responsible

Earlier, prosecutor Robert Horan Jr. told jurors the evidence is "overwhelming" that Malvo was the shooter, saying that Malvo's confession to police weeks after his arrest is more credible than the statements he made "after months with the mental health crowd."

In a dramatic flourish, Horan played portions of Malvo's tape-recorded confession following his October 2002 arrest, and showed a color photo of Franklin laying on the parking lot of the Home Depot store with half of her head missing.

"He intended to hit her in the head. That's what he said. That's what he did," said Horan.

Horan told jurors that some things in the trial are "not seriously in dispute."

"No. 1 is that the killing of Linda Franklin, no matter how you carve it up, the killing of Linda Franklin was a willful, deliberate and premeditated killing."

"These killings, on the evidence in front of you, were done for money. They killed all of these people essentially for money. That's why they did it," Horan said of Malvo and Muhammad. "They wanted to have enough bodies out there that the government would pay attention to them and give them the money.

Concerning the insanity defense, Horan said, "We don't ask you to leave your common sense on the front steps of this courthouse. You're allowed to take your common sense into that jury room with you.

"He (Malvo) was the one looking down the barrel of that weapon. He was the one firing those shots.

"Members of the jury, there is no such thing as a good murder. They don't make them. They're all bad. But some are worse than most. And we submit to you, this one is bad as any."